RFID converter module

ABSTRACT

A tag communication method includes providing a tag reader operating at a first frequency and having transmit and receive antenna ports, providing a frequency converter module having transmit and receive plugs adapted to directly mate with the transmit and receive ports, and directly mating the transmit plug with the transmit port and the receive plug with the receive port. A transmit signal at the first frequency is received from the reader by the converter module by way of the directly mated transmit plug and converted to a second frequency differing from the first frequency to provide a converted transmit signal which is transmitted to the tag. A receive signal is received from the tag at the second frequency and converted to the first frequency to provide a converted receive signal which is applied by the conversion module to the reader by way of the directly mated receive plug.

BACKGROUND OF THE INVENTION

1. Field of Invention

The present invention generally relates to the field of security tags,and more particularly, to a system and method for adding functionalityto security tag readers.

2. Description of Related Art

Several references disclose receiving radio frequency signals at onefrequency and retransmitting them at a different frequency. For example,U.S. Pat. No. 4,622,557, issued to Westerfield on Nov. 11, 1986,discloses reception, downconversion and retransmission of GPS satellitesignals in a system for determining a splashdown location by sonobuoys.The sonobuoys receive the GPS satellite signals, and downconvert them toa baseband frequency using frequency multipliers and filters. A localoscillator and a frequency synthesizer are used to modulate the signalat the new transmit frequency. The modulated signals at the new transmitfrequency are then transmitted to an aircraft.

U.S. Patent Publication No. 2009/0016260 A1 by Thesling discloses agateway for receiving a radio frequency signal at one frequency andtransmitting it on one of a plurality of different frequency channelsbased on priority determinations. U.S. Pat. Nos. 6,215,988 (Matero),6,397,044 (Nash) and 7,162,218 (Axness) also disclose receiving andtransmitting radio frequency signals at different frequencies. However,none of the foregoing references disclose a method for converting tagreader devices operating at one frequency into tag reader devicescapable of operating at different frequencies.

Additionally, U.S. Pat. No. 6,075,972, issued on Jun. 13, 2000 toLaubach, discloses a CATV network having transmitter and receiverappliqué modules. The appliqué modules are added to the network toincrease network functionality. A signal from a cable modem at the homeof the user in the Laubach network is received from a cable modem at afirst frequency by a transmitter appliqué. The transmitter appliquéupconverts the signal is to a second frequency. The transmitter appliquéthen transmits the upconverted signal to a network headend controller.The transmitted signal is received by a receiver appliqué coupled to theheadend controller. It is then downconverted to a third frequency, andapplied to the headend controller by the receiver appliqué.

U.S. Pat. No. 6,362,738, issued to Vega on Mar. 26, 2002, teaches theuse of a plurality of detector circuits operating at differentfrequencies to permit a tag reader to respond to either RFID tags or EAStags. U.S. Pat. No. 7,359,672, issued to Lynch, discloses providingcombined EAS and RFID functionality in a tag communication system. TheLynch system uses much of the same circuitry for multiplying,upconverting and downconverting radio frequency signals in a system forconverting the signals to different frequencies. The frequencyconversion disclosed by Lynch includes conversion between microwave andmillimeter signals. U.S. Pat. No. 6,658,237, issued to Rozenblit on Dec.2, 2003, discloses using a tunable local oscillator for producingmultiple retransmission bands from a baseband signal. For example, theretransmission bands can be the different frequency bands assigned todifferent cells in a mobile telephone communication system, such asfrequencies in the range of 890 Mhz to 960 MHz. U.S. Patent PublicationNo. 2009/0117938 A1, filed on Nov. 2, 2007 by Georgantas, discloses asystem with a plurality of receive frequencies and a plurality oftransmit frequencies. However, none of the foregoing references disclosea system or method for converting tag reader devices operating at onefrequency into tag reader devices capable of operating at differentfrequencies.

Thus, there remains a need for a method for conveniently converting tagreaders operating at one frequency into tag readers capable of operatingat different frequencies.

All references cited herein are incorporated herein by reference intheir entireties.

BRIEF SUMMARY OF THE INVENTION

A module includes a first receiver port configured to receive a readertransmit signal at a first frequency and a first frequency converterconfigured to convert the reader transmit signal to a second frequencyto provide a converted reader transmit signal, the second frequencydiffering from the first frequency. A first transmit port is configuredto transmit the converted reader transmit signal to a tag. A secondreceiver port is configured to receive a tag transmit signal from a tag.A second frequency converter is configured to convert the tag transmitsignal to the first frequency to provide a converted tag transmitsignal. A second transmit port is configured to transmit the convertedtag transmit signal to the reader. A baseband converter converts thereader transmit signal to provide a baseband transmit signal. The readertransmit signal is an encoded reader transmit signal and the basebandtransmit signal is an encoded baseband transmit signal. Decodercircuitry decodes the encoded baseband transmit signal to provide adecoded baseband signal. The reader transmit signal is encoded with afirst coding scheme and encoding circuitry encodes the decoded basebandsignal with a second encoding scheme differing from the first encodingscheme to provide a further encoded baseband signal.

A tag security system having a tag, includes a frequency convertermodule configured to be coupled to: (i) a directly mated transmit plugthat is directly mated with a transmit antenna port of a tag readeroperating at a first frequency, and (ii) a directly mated receive plugthat is directly mated with a receive antenna port of the tag reader.The frequency converter module includes a transmit frequency convertercircuitry for receiving a transmit signal at the first frequency fromthe tag reader by way of the directly mated transmit plug, convertingthe transmit signal to a second frequency differing from the firstfrequency to provide a converted transmit signal, and transmitting theconverted transmit signal to the tag. Additionally, the frequencyconverter module includes receive frequency converter circuitry thatreceives a receive signal at the second frequency from the tag, convertsthe receive signal to the first frequency to provide a converted receivesignal, and applies the converted receive signal to the tag reader byway of the directly mated receive plug.

A communication method in a tag security system having a tag includesproviding a tag reader operating at a first frequency and having atransmit antenna port and a receive antenna port, providing a frequencyconverter module having a transmit plug and a receive plug adapted todirectly mate with the transmit port and the receive port, respectively,and directly mating the transmit plug with the transmit port and thereceive plug with the receive port to provide a directly mated transmitplug and a directly mated receive plug. A transmit signal at the firstfrequency is received from the tag reader by the frequency convertermodule by way of the directly mated transmit plug and the transmitsignal is converted to a second frequency differing from the firstfrequency to provide a converted transmit signal. The converted transmitsignal is transmitted to the tag by the frequency conversion module. Areceive signal is received from the tag at the second frequency and thereceive signal is converted to the first frequency to provide aconverted receive signal. The converted receive signal is applied by thefrequency conversion module to the tag reader by way of the directlymated receive plug.

The transmit signal is baseband downconverted to provide a downconvertedbaseband transmit signal. The transmit signal is an encoded transmitsignal, the downconverted baseband transmit signal is an encodedbaseband signal, and the encoded baseband signal is decoded to provide adecoded baseband signal. Clock recovery is performed on the decodedbaseband signal. The transmit signal is encoded with a first codingscheme and the decoded baseband signal is encoded with a second encodingscheme differing from the first encoding scheme to provide a furtherencoded baseband signal. The further encoded baseband signal istransmitted by the frequency converter module.

The first frequency can be an EAS frequency, and the second frequencycan be an RFID frequency. The first frequency can be an RFID frequency,and the second frequency can be an EAS frequency. The second frequencycan be a wireless frequency such as the WiFi wireless frequencies of 2.4GHz, 3.6 GHz and 5 GHz. Communication is provided between the tag readerand a computer by way of the wireless frequency. Antitheft operationsare monitored by the computer by way of the wireless system. Logisticaloperations are monitored by the computer by way of the wireless system.Communication is provided between the tag and the internet by way of thewireless frequency.

A further frequency converter module is provided, and the transmitsignal is converted to a third frequency differing from the first andsecond frequencies to provide a further converted transmit signal. Thefurther converted transmit signal is transmitted to a tag by the furtherfrequency conversion module. Communication with a combination tag isprovided by way of the first frequency and the third frequency.Communication with a combination tag is provided by way of the secondfrequency and the third frequency. The converted transmit signal istransmitted to a further tag reader by the frequency conversion module.

An EAS to RFID converter module coupled to the preexisting transmitantenna port of an EAS reader receives an 8.2 MHz EAS transmit signalfrom the EAS reader. The 8.2 MHz EAS signal received by the EAS to RFIDconverter module is the signal that would be transmitted to an EAS tagby an EAS antenna plugged into the reader transmit antenna port, if theEAS reader is not converted into an RFID reader by the EAS to RFIDconverter module of the invention. The EAS to RFID converter moduleupconverts the 8.2 MHz EAS transmit signal from the reader transmit portto a 900 MHz RFID signal, and transmits the resulting upconverted 900MHz RFID signal to an RFID tag.

The EAS to RFID converter module is coupled to the preexisting receiveantenna port of the EAS reader for receiving a 900 MHz RFID signal froman REID tag, downconverting the 900 MHz RFID receive signal to an 8.2MHz EAS signal, and applying the downconverted 8.2 MHz EAS signal to thereceive antenna port of the EAS reader. The 8.2 MHz EAS signal receivedby the reader from the EAS to RFID converter module is the kind ofsignal that would be received by an antenna plugged into the readerreceive port, if the EAS reader is not converted into an RFID reader bythe EAS to RFID converter module.

In another embodiment of the invention, an RFID to EAS converter moduleis coupled to the transmit and receive antenna ports of an RFID reader,for converting the frequencies of transmitted and received signals, inorder to provide EAS functionality to the RFID reader. In thisembodiment, the RFID to EAS converter module receives a 900 MHz RFIDtransmit signal from the preexisting transmit antenna port of the RFIDreader. The 900 MHz RFID signal received from the reader is the signalthat would be transmitted by an antenna plugged into the transmit port,if the RFID reader is not converted into an EAS device by an RFID to EASconverter module. The RFID to EAS converter module downconverts the 900MHz RFID transmit signal to an 8.2 MHz EAS signal, and transmits theresulting downconverted 8.2 MHz EAS signal to an EAS tag. EAS signalsreceived from the tag by the RFID to EAS converter module areupconverted and applied to the receive antenna port of the RFID reader.

BRIEF DESCRIPTION OF SEVERAL VI WS OF THE DRAWINGS

The invention will be described in conjunction with the followingdrawings in which like reference numerals designate like elements andwherein:

FIG. 1 shows a schematic representation of an embodiment of a frequencyconverter system including an embodiment of the frequency convertermodule of the present invention for use within tag communicationsystems.

FIG. 2 shows a schematic representation of a frequency converter systemincluding an alternate embodiment of the frequency converter module ofFIG. 1.

FIG. 3 shows a schematic representation of a frequency converter systemincluding an alternate embodiment of the frequency converter module ofFIG. 1.

FIG. 4 shows a schematic representation of an alternate embodiment ofthe frequency converter system of FIG. 1.

FIG. 5 shows a schematic representation of a retail space using thefrequency converter system of FIG. 4.

FIG. 6 shows a schematic representation of the frequency convertersystem of FIG. 1 within a configurable monitoring device system.

DETAILED DESCRIPTION OF THE INVENTION

Referring now to FIG. 1, there is shown a schematic representation ofthe frequency converter system 10 of the present invention for usewithin tag communication systems. The frequency converter system 10includes a transmit/receive EAS reader 12 having antenna ports 14 a,b.The antenna port 14 a can be a transmit antenna port suitable for matingwith an EAS transmit antenna, and the antenna port 14 b can be a receiveantenna port suitable for mating with an EAS receive antenna.

The frequency converter system 10 also includes a frequency convertermodule 30. The frequency converter module 30 is provided with a transmitcable 18 a and a receive cable 18 b, which can be attached to respectiveports on the frequency converter module 30. The cables 18 a,b haverespective plugs 16 a,b. The transmit plug 16 a can mate directly withthe transmit antenna port 14 a of the EAS reader 12, for receiving atransmit signal from the transmit antenna port 14 a, and applying thetransmit signal to a receiver port of the frequency converter module 30by way of the transmit cable 18 a. The transmit signal received by thetransmit plug 16 a is substantially the same transmit signal that wouldbe received by a transmit antenna if a transmit antenna is coupled tothe transmit antenna port 14 a. The transmit signal can be, for example,an 8.2 MHz signal. Additionally, the receive plug 16 b can mate directlywith the antenna receive antenna port 14 b for applying a receive signalfrom a transmit port of the frequency converter module 30 to the receiveantenna port 14 b of the EAS reader 12. The receive signal applied bythe receive plug 16 b is substantially the same receive signal thatwould be applied by a receive antenna if a receive antenna is coupled tothe receive antenna port 14 b.

The transmit signal received from the EAS reader 12 by way of thedirectly mated transmit plug 16 a is applied to a first frequencyconverter including the upconverter 22 a within the frequency convertermodule 30 for upconversion. A conventional upconverting mixer canperform the upconverting within the upconverter 22 a. An 8.2 MHztransmit signal from the EAS reader 12 can be upconverted to a 900 MHztransmit signal. If the upconverted transmit signal is a 900 MHz signal,an 891.8 MHz local oscillator can be used for upconversion by theupconverter 22 a. The upconverted transmit signal from the upconverter22 a can be filtered and amplified by the filter/amplifier 34 a.Filtering by the filter/amplifier 34 a is useful for lowering the noiseof the upconverted transmit signal and removing the jitter from thetransmit signal. The amplification is preferably very low noiseamplification, since mixers within upconverter and downconvertercircuitry typically have a high noise figure and can add significantnoise to the signals. The filtered and amplified signal from thefilter/amplifier 34 a is then applied by way of a transmit port of thefrequency converter module 30 and the transmit cable 36 a to a transmitantenna (not shown) for transmission to a tag.

Additionally, a 900 MHz antenna (not shown) can receive a 900 MHz signalfrom a tag, and apply the receive signal to the frequency convertermodule 30 of the frequency converter system 10 by way of the receivecable 36 b and a receiver port of the frequency converter module 30. Thereceive signal from the receive cable 36 b can be bandpass filtered, toremove any out of band signals, and amplified by the filter/amplifier 34b. The filtered and amplified receive signal can then be downconvertedby a second frequency converter including the downconverter 22 b. Thedownconverter 22 b can use the previously described 891.8 MHz localoscillator 26 to perform the downconversion of the receive signal. Thedownconverted signal from the downconverter 22 b can be applied to thereceive antenna port 14 b of the EAS reader 12 by way of the receivecable 18 b and the directly mated receive plug 16 b.

Thus, the frequency converter module 30 of the frequency convertersystem 10 can be coupled directly to the preexisting transmit andreceive antenna ports 14 a,b of the EAS reader 12 for performingfrequency conversions using first and second frequency converters. Forexample, if the EAS reader 12 is an 8.2 MHz device, the frequencyconversion module 30 can include frequency converters to adapt thereader 12 to send and receive signals with 900 MHz tags. The preexistingtransmit port 14 a and the preexisting receive port 14 b of the EASreader 12 are ports on the reader that are originally adapted to becoupled to 8.2 MHz transmit and receive antennas for transmitting andreceiving 8.2 MHz radio frequency signals. The plugs 16 a,b on thecables 18 a,b are adapted to directly mate with the preexisting ports 14a,b in substantially the same manner that the 8.2 MHz transmit andreceive antennas would mate with the preexisting ports 14 a,b if the tagreader 12 is used in an 8.2 MHz communication system. The frequencyconverter module 30 is thus adapted to plug directly into thepreexisting ports of the tag reader 12, where the transmit and receiveantennas would be plugged, in order to convert the tag reader 12 for usein a 900 MHz system, without any modifications of the tag reader 12.

In one embodiment of the frequency converter module 30 the RFID signalscan be frequency hopped. For example, the RFID signals can be frequencyhopped over a range of 902 MHz to 928 MHz, under the control of the tagreader 12. The hopping can occur with a predetermined period, forexample, every 400 millisecond, over a predetermined number of channels,for example over fifty channels. The tag reader 12 can use a preexistingcontrol channel within the tag reader 12, for example a general purposeinput/output port, to apply control signals to the frequency convertermodule 30 regarding when to hop and which channels to hop to.Additionally, the tag reader 12 can apply the control signals to thefrequency converter module 30 by way of a data port. In the later case,the control signals and the data signals can be separated in frequency.For example, the tag reader 12 can send the data over an 8.2 MHz channelwhile sending the control signals between DC and 100 KHz.

Referring now to FIG. 2, there is shown a schematic representation ofthe frequency converter system 40. The frequency converter system 40 isan alternate embodiment of the frequency converter system 10. Atransmit/receive tag reader 42 operating at a first frequency isprovided with a frequency converter module 50 within the frequencyconverter system 40 for adapting the tag reader 42 to operate at asecond frequency different from the first frequency. Additionally,baseband downconversion and decoding functionality are provided withinthe frequency converter module 50.

In the frequency converter system 40 a transmit signal from the EASreader 42 is coupled to the baseband downconverter 72 a within thefrequency converter module 50 by way of a transmit cable 48 a having atransmit plug 46 a. The transmit plug 46 a mates directly with apreexisting transmit port 44 a of the EAS reader 42 to receive thetransmit signal from the transmit port 44 a. The transmit signalreceived by way of the transmit port 44 a can be any frequency. Forexample, the transmit signal can be an 8.2 MHz signal. The basebanddownconverter 72 a downconverts the transmit signal to the basebandusing an 8.2 MHz local oscillator 74 in order to permit it to bedecoded. The downconverted baseband transmit signal is applied to thefilter/amplifier 76 a.

The filtered and amplified baseband signal from the filter/amplifier 76a in the frequency converter module 50 can then be applied to the decodeand retransmit block 78 a for decoding and retransmission. The decodingperformed within the frequency converter system 40 by the decode andretransmit block 78 a can be any kind of decoding known to those skilledin the art. For example, the decoding can be CDMA decoding. The use ofCDMA encoding and decoding in modulated backscatter systems, includingthe use of the CDMA encoding for range extension, is disclosed in moredetail in copending U.S. application Ser. No. 12/406,629, filed on Mar.18, 2009, which is incorporated by reference herein. After the decoding,the signal can be reencoded and prepared for retransmission within thedecode and retransmit block 78 a.

The decode and retransmit block 78 a can be used to convert from onetype of code to another, by recoding a signal in a different code afterit is decoded. This can be useful where coding schemes in one frequencyare not suitable for use in another frequency, for example because ofthe different coding complexities permitted at the different transmitand receive frequencies. In another embodiment, a signal can be decodedby the decode and retransmit block 78 a, and retransmitted with noreencoding. Additionally, a signal with no encoding can be received bythe decode and retransmit block 78 a and retransmitted with encoding. Inanother embodiment, the decode and retransmit block 78 a can be disabledand the signal can be prepared for retransmission without performing anydecoding or encoding operations.

The retransmission signal from the decode and retransmit block 78 a canbe upconverted by the upconverter 52 a using the local oscillator 56.For example, the retransmission signal from the decode and retransmitblock 78 a can be upconverted to 900 MHz using a 900 MHz localoscillator 56. The upconverted signal from the upconverter 52 a isamplified and filtered by the amplifier/filter 64 a for removing noiseand jitter. The amplified and filtered signal is then transmitted by thefrequency converter system 40 using a transmit antenna (not shown)coupled to the transmit cable 66 a.

A receive signal can be received from a tag and applied to theamplifier/filter 64 b of the frequency converter module 50 by way of anantenna (not shown) coupled to the receive cable 66 b. In one embodimentof the invention the receive signal can be a 900 MHz signal. Theamplified and filtered receive signal from the amplifier/filter 64 b canthen be downconverted to baseband using the downconverter 52 b. Thedownconverted baseband receive signal can be decoded by the decode andretransmit block 78 b. The operations performed within the decode andretransmit block 78 b can include any kind of decoding and encodingknown to those skilled in the art, as previously described.

After the decoding or reencoding, the signal can be prepared forretransmission within the decode and retransmit block 78 b. In analternate embodiment, the signal can be prepared for retransmissionwithout performing any decoding operations. The retransmission signal isfiltered and amplified in filter/amplifier 76 b, downconverted bydownconverter 72 b, and applied to the preexisting receive antenna port44 b of the EAS reader 42 by way of the receive cable 48 b and thedirectly mated receive plug 46 b.

Referring now to FIG. 3, there is shown a schematic representation ofthe frequency converter system 80, including the frequency convertermodule 90, which is an alternate embodiment of the frequency convertermodules 30, 50. In the frequency converter module 90 a transmit signalfrom an EAS reader is coupled to the baseband downconverter 88 a by wayof a transmit cable 84 a having a transmit plug 82 a. The transmit plug82 a plugs into a preexisting transmit port of the EAS reader. Thetransmit signal can be, for example, an 8.2 MHz signal. The basebanddownconverter 88 a downconverts the transmit signal to the basebandusing an 8.2 MHz local oscillator 92. The downconverted basebandtransmit signal is applied to the filter/amplifier 94 a. Clock recoveryand data recovery (CDR) can be performed on the signal fromfilter/amplifier 94 a within the CDR block 98 a of the frequencyconverter module 90 in order to improve the quality of the data and thesignal integrity of the transmit signal.

The filtered and amplified baseband signal from the CDR block 98 a inthe frequency converter module 90 can then be applied to the decode andretransmit block 104 a for decoding and retransmission. In an alternateembodiment, the signal can be prepared for retransmission withoutperforming any decoding operations. The retransmission signal from thedecode and retransmit block 104 a can be upconverted by the upconverter112 a using the local oscillator 114. The upconverted signal from theupconverter 112 a is amplified and filtered by the amplifier/filter 116a and transmitted by way of an antenna (not shown) coupled to thetransmit cable 118 a.

A receive signal can be received and applied to the amplifier/filter 116b of the converter 80 by way of an antenna (not shown) coupled to thereceive cable 118 b. The amplified and filtered receive signal from theamplifier/filter 116 b can then be downconverted to baseband using thedownconverter 112 b. CDR can be performed on the baseband signal withinthe CDR block 98 b of the frequency converter module 90 in order toimprove the quality and the data and the signal integrity of the receivesignal. The signal can then be decoded by the decode and retransmitblock 104 b. The decoding within the decode and retransmit block 104 bcan be any kind of decoding known to those skilled in the art.

After the decoding, the signal can be prepared for retransmission withinthe decode and retransmit block 104 b. The retransmission signal isfiltered and amplified in filter/amplifier 94 b, downconverted bydownconverter 88 b, and applied to the preexisting receive antenna portof the EAS reader by way of the receive cable 84 b and the receive plug82 b.

Thus, it will be understood by those skilled in the art, that the systemand method of the present invention include frequency converter modulesthat are coupled directly to the preexisting transmit and receiveantenna ports of tag readers, for performing frequency conversion. Thepreexisting transmit and receive ports in the present invention can beports provided on the readers at the time of the manufacture of thereaders. The preexisting ports can be originally adapted to mate withtransmit and receive antennas, for transmitting and receiving thefrequency signals of the tag readers. The plugs of the frequencyconverter modules of the invention are adapted to plug directly into thepreexisting ports at the location, where the transmit and receiveantennas would be plugged, if the frequency converter modules were notused. Thus, modifications of the reader ports are not needed in order toprovide the frequency conversions of the invention.

In one embodiment of the invention, an EAS to RFID frequency convertermodule can be coupled to the transmit and receive antenna ports of anEAS reader, for converting the frequencies of the transmitted andreceived signals, in order to provide RFID functionality to the EASreader. For example, the frequency converter modules 30, 50 are shown asfrequency converter modules for converting between EAS and RFID asrequired to provide RFID functionality to EAS readers.

However, in another embodiment of the invention, an RFID to EASconverter module can be coupled to the transmit and receive antennaports of an RFID reader. Such a frequency converter module can convertthe frequencies of the transmitted and received signals of the RFIDreader to provide EAS functionality to the RFID reader. In thisembodiment, the RFID to EAS converter module receives a 900 MHz RFIDtransmit signal from a preexisting RFID reader transmit antenna port.The 900 MHz RFID signal received by the RFID to EAS converter module isthe signal that would be transmitted by an RFD antenna plugged into thetransmit port, if the RFID reader is not converted into an EAS device bythe RFID to EAS converter module. The RFID to EAS converter moduledownconverts the 900 MHz RFID transmit signal to an 8.2 MHz EAS transmitsignal, and transmits the resulting downconverted 8.2 MHz EAS signal toan EAS tag. In an alternate embodiment of the invention the 900 MHz RFIDtransmit signal can be decoded and retransmitted prior to conversion toan EAS signal.

The RFID to EAS converter module coupled to the preexisting receiveantenna port of the RFID reader receives an 8.2 MHz signal from the EAStag, upconverts the 8.2 MHz signal receive to an 900 MHz RFID signal,and applies the upconverted signal to the preexisting receive antennaport of the RFID reader. The receive signal can be decoded andretransmitted prior to being applied to the RFID receive port.

Thus, the frequency converter modules of the invention provide theadvantage of performing the foregoing frequency conversions by directlycoupling to the preexisting antenna ports, thereby allowing easyconversions from, for example, EAS to RFID, and from RFID to EAS. Thefrequency converter modules include mixers, filters, amplifiers andother circuitry as needed in order to perform the requiredupconversions, downconversions, encoding, decoding and retransmissions.

Furthermore, it will be understood that frequency converter modulesconverting between any other frequencies can also be provided accordingto the invention. This includes converter modules for converting betweenall of the frequencies that are conventionally used for communicationwith tags. For example, the Table below shows many of the frequenciesthat can be used in tag communications systems. The system and method ofthe present invention can perform frequency conversions between any ofthe frequencies shown, including conversions between different EASfrequencies and conversions between different RFID frequencies, as wellas between EAS and RFID frequencies.

TABLE EAS Operation RFID Operation Low Frequency (LF)  5 kHz-14 kHz HighFrequency (HF)   2 MHz-14 MHz Acousto-Magnetic (AM) 50 kHz-70 kHzUltrahigh Frequency (UHF)  850 MHz-950 MHz Radio Frequency (RF)  2MHz-14 MHz Microwave Frequency  2.3 GHz-2.6 GHz

Additionally, the system and method of the present invention can includefrequency conversion modules for converting between any of the known tagfrequencies, and any other frequencies not conventionally used in tagcommunication systems, such as WiFi frequencies, as discussed in moredetail below. Additionally, converter modules can be provided forconverting between the frequency of the tag reader and multiplefrequencies, as discussed in more detail below.

Referring now to FIG. 4, there is shown a schematic representation ofthe multifrequency converter system 130. The multifrequency convertersystem 130 includes a transmit/receive tag reader 132, which can be anytype of tag reader operating at a frequency F_(R). The frequency F_(R)can be any tag frequency known to those skilled in the art. For example,the frequency F_(R) can be 8.2 MHz, 860 MHz, 900 MHz, 915 MHz or 950MHz. A transmit signal at frequency F_(R) is received from the tagreader 132 at the transmit port 134 a by the transmit plug 136 a and thedirectly mated transmit cable 138 a, in the manner described above.Additionally, a receive signal at the frequency F_(R) is applied to thereceive port 134 b of the tag reader 132 by way of the directly matedreceive cable 138 b and the receive plug 136 b.

The multifrequency converter system 130 also includes the convertermodule group 140. The converter module group 140 can include any numbern of frequency converter modules 150 a-n, operating at their respectivefrequencies F_(a) through F_(n). The frequencies F_(a) through F_(n) canbe any frequencies whatsoever. Thus, each frequency converter module 150a-n can perform frequency conversions between the frequency F_(R) of thetag reader 132 and its respective frequency F_(a) through F_(n) in themanner previously described. In an alternate embodiment, the tag reader132 can be provided with a plurality of transmit ports and/or aplurality of receive ports for separately mating with the plugs andcables of the plurality of converter modules 150 a-n. Additionally, thetag reader 132 can be converted to provide transmit signals in onefrequency and receive signals in another differing frequency using thefrequency converter modules of the invention.

Furthermore, the frequencies F_(a) through F_(n) are not limited to tagfrequencies. For example, it will be understood that any one of thefrequencies F_(a) through F_(n) can be a wireless frequency such as theWiFi wireless frequencies of 2.4 GHz, 3.6 GHz and 5 GHz. In theembodiment of the converter module group 140 shown, the frequency F_(n)is a wireless network frequency such as a WiFi network frequency. Forexample, the frequency F_(n) can be selected to provide access tonetworks of configurable monitoring devices of any type therebyproviding access to any of the protocols available in the configurablemonitoring systems. Such configurable monitoring systems are describedin more detail in copending application Ser. No. 12/878,546 filed Sep.9, 2010 entitled Calibration of Beamforming Nodes in a ConfigurableMonitoring Device System and Ser. No. 12/879,049 filed Sep. 10, 2010entitled Localizing Tagged Assets In A Configurable Monitoring DeviceSystem, both of which are incorporated by reference herein in theirentirety. Thus, the transmit frequency F_(R) of the tag reader 132 isconverted and transmitted to a wireless network 154 by the wirelessantennas 152 coupled to the frequency converter module 150 n.Additionally, signals from the wireless network 154 are received by thewireless antennas 152, converted to the frequency F_(R), and applied thetag reader 132 by way of the frequency converter module 150 n. In thismanner, the tag reader 132 is provided with access to all of thecomputers, databases, communications protocols, link network protocolsand equipment compatibility available in the wireless domain, includingaccess to any type of configurable monitoring devices by providingfrequency conversions to and from any frequencies that may be used bysuch configurable monitoring devices.

In one preferred embodiment of the invention, the frequency F_(R) can be900 MHz, the frequency F_(n) can be a conventional wireless frequencysuch as 2.4 GHz, and at least one of the remaining frequency convertermodules 150 a-(n−1) can operate at an EAS frequency such as 8.2 MHz.This system allows the advantages of EAS for loss prevention andantitheft operations in the EAS domain, the logistics operationsavailable in, for example, the 900 MHz RFID domain, and all of theprotocols and equipment networking of the WiFi domain. Additionally,such a system can be used with combination EAS/RFID tags, since both 900MHz and 8.2 MHz transmission and reception are available forcommunication with such tags.

Referring now to FIG. 5, there is shown a schematic representation of aretail space 170. The retail space 170 includes a back store region 172and a front store region 174. The back store region 172 and the frontstore region 174 are separated by a wall with a portal 182, throughwhich store personnel and items to be tracked can pass. Atransmit/receive tag security system 180 can be located at the portal182 for logistical monitoring, such as the monitoring of the movement ofthe items to be tracked and, in some embodiments, the movement of thestore personnel through the portal 182. The logistical operationsmonitored by the tag security system 180 can be any kind of logisticaloperations known to those skilled in the art. In a preferred embodiment,the tag security system 180 can be a 900 MHz transmit/receive system,since 900 MHz systems are well suited to performing such logisticalmonitoring. The front store region 174 has a gate 192 through whichshoppers and items to be tracked can pass. Additionally, atransmit/receive tag security system 190 can be located at the gate 192in order to deter theft of the items to be tracked.

The tag security system 190 can be a multifrequency converter systemhaving a plurality of frequency converter modules, such as themultifrequency converter system 130 described above. In a preferredembodiment of the invention, the frequency of the tag reader within amultifrequency tag security system 190 can be 900 Mhz. One frequencyconverter module within the multifrequency tag security system 190 canbe an 8.2 MHz frequency converter module. Another frequency convertermodule within the multifrequency tag security system 190 can be a 2.4GHz converter. In this manner, the 8.2 MHz frequency converter modulecan be used for antitheft monitoring at the gate 192. The 900 MHz tagreader in the tag security system 190 at the gate 192 can be adapted tocommunicate with the tag security system 180 at the portal 182.Additionally, the tag reader and the frequency conversion modules in thetag security system 190 can be used to monitor combination EAS/RFID tagsin the vicinity of the gate 192, if such tags are used.

Furthermore, a 2.4 GHz frequency converter module within themultifrequency tag security system 190 can couple the tag securitysystems 180, 190 to a WiFi network. In this manner, the logisticaloperations and the antitheft operations of the tag security systems 180,190 can be coupled to any computers, databases and other equipmentavailable to the retail space 170. Additionally, the operations of thetag security systems 180, 190 can be coupled to the internet by way ofthe 2.4 GHz.

Referring now to FIG. 6, there is shown a configurable monitoring system60 that includes a number of configurable monitoring devices in variousroles, including at least one configurable monitoring device configuredto operate as a frequency conversion module of the invention.Additionally, any of the devices 68 a-68 i may be configurablemonitoring device tags affixed to a product for the purpose ofsupporting security, inventory, marketing, as well as otherfunctionalities. Network activity nodes 67 (e.g., nodes 67 a-67 c) maybe configured to support network level activities such as communicationsrouting, tag locating, and the like.

Gateway node 69 may be configured as a gateway node to provide a networkinterface between the monitoring system 60 and the external network 32.A monitoring terminal 62 may be in communication with the gateway node69, for example, via the external network 32 or via a direct connectionto the gateway node 69, to facilitate management of the configurablemonitoring devices by the monitoring terminal 62 and to furtherfacilitate the aggregation and analysis of data received from theconfigurable monitoring devices. A gateway node may interface with acellular network to gain access to other networks, such as the Internet.In some example embodiments, a gateway node may support USB and Ethernetconnectivity for connection to USB or Ethernet networks.

The gateway node 69 may also include or be associated with a networkcoordinator. The network coordinator may be configured to oversee andmanage various network operations. For example, the network coordinatormay implement the forming of the network, allocate network addresses toentities of the network, and maintain a binding table for the network.

In some cases, the monitoring system 60 may be made up of a plurality ofcommunication devices (e.g., such as a plurality of configurablemonitoring devices) in communication with each other viadevice-to-device communication to form a mesh network. However, in othersituations, the network may include a plurality of devices that transmitsignals to and receive signals from a base site or access point, whichcould be, for example a base site or access point of a data network,such as a local area network (LAN), a metropolitan area network (MAN),and/or a wide area network (WAN), such as the Internet.

Other devices such as processing elements or devices (e.g., personalcomputers, server computers, displays, point of sale (POS) terminalsand/or the like) may be coupled to a configurable monitoring device toaccess the monitoring system 60. By directly or indirectly connectingthe configurable monitoring devices to various network devices and/or toother configurable monitoring devices via the monitoring system 60, theconfigurable monitoring devices may be enabled to receive configurationmodifications dynamically and perform various functions or tasks inconnection with network devices or other configurable monitoring devicesbased on the current configuration of the configurable monitoringdevices.

The configurable monitoring devices may support any type of RFIDcommunications within the frequency converter systems 10, 40, 80, 130,such as communications based frequencies within the on Generation IIUltra High Frequency (UHF) RFID standards. In example embodiments wherea configurable monitoring device includes a radio (e.g., an IEEE802.15.4 radio) and an RFID module, the configurable monitoring devicemay be configured to operate as an interface that allows RFID devices toaccess the monitoring system 60. For example, an RFID reader or otherRFID device, that does not include a configurable monitoring device, maycommunicate with a configurable monitoring device, such as a tag, andthe configurable monitoring device may relay such communications toentities connected to the monitoring system. In the same manner, the tagmay relay communications originating on the monitoring system to an RFIDdevice that has interfaced with a tag. As such, the configurablemonitoring devices may operate as gateways to the monitoring system forRFID communications.

The monitoring system 60 may be configured to operate as a mesh networkor a hybrid mesh network. In some example embodiments, the monitoringsystem is configured in a star network structure, a hybrid star networkstructure, a cluster tree or the like. In this regard, the monitoringsystem 60 may support message hopping and network self-healing. Withrespect to message hopping, the nodes 67 may be configured to receivecommunications from nearby or assigned tags 68. The nodes 67 may beconfigured to determine a system architecture and/or efficient pathwaysfor communicating messages to the various entities within the network.In this regard, the nodes 67 may be configured to generate and maintainrouting tables to facilitate the efficient communication of informationwithin the network.

For example, in accordance with implemented marketing functionality, tag68 h may be configured to communicate that the product that tag 68 h isaffixed to has been moved from its display location. Tag 68 h may beconfigured to communicate this information to tags 68 g and 68 d,because the products affixed to tags 68 g and 68 d are related productsthat a customer may be interested in purchasing, given the customer'sapparent decision to purchase the product affixed to tag 68 h.Accordingly, tag 68 h may generate and transmit a message addressed totags 68 g and 68 d. The message may be received by node 67 c, and node67 c may be configured to determine how to route the message, givencurrent network traffic, such that the message is efficiently receivedby tags 68 g and 68 d. For example, using generated routing tables, node67 c may determine that the message can first be transmitted directly totag 68 g, since tag 68 g is connected to or in direct communication withthe node 67 c. To transmit the message to tag 68 d, node 67 c maydetermine that the message should be forwarded to node 67 b. Node 67 bmay perform a similar analysis and determine that the message can beforward to tag 68 d, directly from node 67 b. Tag 68 h may also beconfigured to transmit the message to the monitoring terminal 62. Node67 c may route the message accordingly, such that the gateway 64 mayforward the message to the monitoring terminal 62.

As indicated above, the nodes 67 may be configured to performcommunications routing within the monitoring system 60. In this regard,nodes 67 may operate to extend the range of the monitoring system.However, according to some example embodiments, all configurablemonitoring devices within the monitoring system 60 may be configured toperform routing functionality. As such, configurable monitoring devicesconfigured to operate both as tags and as nodes may communicate directlywith each other, if within range, without having to route thecommunications through another node. Nodes within the monitoring system60 may also be configured to operate as beamforming nodes, calibrationnodes, or localizing nodes.

Additionally, the monitoring system 60 may be configured to compensatefor interference and multi-path conditions that can arise in enclosedenvironments, such as retail stores. To do so, the monitoring system 60may be configured, for example by the monitoring terminal 62, to modifythe signal power of select nodes and tags to minimize interference.According to some example embodiments, directional antennas may also beused by configurable monitoring devices to minimize interference.

According to various example embodiments, the monitoring system 60 maybe configured to interface with any number of other types of networksand/or systems. For example, the monitoring system 60 may interface withEAS systems, RFD systems, closed circuit television systems, inventorysystems, security systems, sales systems, shipping systems, point ofsale terminals, advertising systems, marketing compliance systems,ordering systems, restocking systems, virtual deactivation systems,Lojack® systems, and the like.

Based on the foregoing, and in accordance with some example embodiments,the nodes may be configured to provide a wireless signal that may bereceived by tags that are within range. According to some exampleembodiments, the range of a node or the power of the signal provided bythe node may be set based on the size of the area that the node isresponsible for. For example, if the node is associated with a smallfloor display, the signal power may be relatively low. On the otherhand, if a node is responsible for a large shelf unit, the signal powermay be set to a higher level to ensure coverage of the entire shelfunit.

While the invention has been described in detail and with reference tospecific examples thereof, it will be apparent to one skilled in the artthat various changes and modifications can be made therein withoutdeparting from the spirit and scope thereof.

What is claimed is:
 1. An apparatus for use in a tag security systemhaving a tag, comprising: a frequency converter module configured to becoupled to (i) a transmit plug directly mated with a transmit antennaport of a tag reader operating at a first frequency to provide adirectly mated transmit plug, and (ii) a receive plug directly matedwith a receive antenna port of the tag reader to provide a directlymated receive plug; the frequency converter module having a transmitfrequency converter for receiving a reader transmit signal at the firstfrequency from the tag reader by way of the directly mated transmitplug, converting the reader transmit signal to a second frequencydiffering from the first frequency to provide a converted readertransmit signal, and transmitting the converted reader transmit signalto a tag; and a receive frequency converter for receiving a tag transmitsignal at the second frequency from the tag, converting the tag transmitsignal to the first frequency to provide a converted tag transmitsignal, and applying the converted tag transmit signal to the tag readerby way of the directly mated receive plug.
 2. The apparatus of claim 1,further comprising a baseband converter for converting the readertransmit signal to provide a baseband transmit signal.
 3. The apparatusof claim 1, wherein the reader transmit signal is an encoded readertransmit signal and the baseband transmit signal is an encoded basebandtransmit signal further comprising decoder circuitry for decoding theencoded baseband signal to provide a decoded transmit baseband signal.4. The apparatus of claim 3, wherein the reader transmit signal isencoded with a first coding scheme and the decoded baseband signal isencoded with a second encoding scheme differing from the first encodingscheme to provide a further encoded baseband signal.
 5. The apparatus ofclaim 1, wherein the second frequency comprises a wireless frequencyfurther comprising a communication between the tag reader and a computerby way of the wireless frequency.
 6. The apparatus of claim 1,comprising a further transmit frequency converter for converting thereader transmit signal to a third frequency differing from the first andsecond frequencies to provide a further converted reader transmit signaland transmitting the further converted reader transmit signal.
 7. Theapparatus of claim 6, further comprising a communication with acombination tag by way of the third frequency and at least one of thefirst and second frequencies.
 8. A communication method, comprising:providing a frequency converter module configured to be coupled to (i) atransmit plug directly mated with a transmit antenna port of a tagreader operating at a first frequency to provide a directly matedtransmit port, and (ii) a receive plug directly mated with a receiveantenna port of the tag reader to provide a directly mated receive port;receiving a reader transmit signal at the first frequency from the tagreader by the frequency converter module by way of the directly matedtransmit plug, converting the reader transmit signal to a secondfrequency differing from the first frequency to provide a convertedreader transmit signal, and transmitting the converted reader transmitsignal to a tag; and receiving a tag transmit signal from the tag at thesecond frequency, converting the tag transmit signal to the firstfrequency to provide a converted tag transmit signal, and applying theconverted tag transmit signal to the tag reader by way of the directlymated receive plug.
 9. The communication method of claim 8, wherein thefirst frequency comprises an EAS frequency and the second frequencycomprises an RFID frequency.
 10. The communication method of claim 8,wherein the first frequency comprises an RFID frequency and the secondfrequency comprises an EAS frequency.
 11. The communication method ofclaim 8, wherein the second frequency comprises a wireless frequency forproviding communication between the tag reader and a computer by way ofthe wireless frequency.
 12. The communication method of claim 8, furthercomprising converting the transmit signal to a third frequency differingfrom the first and second frequencies to provide a further convertedtransmit signal and transmitting the further converted transmit signalto a tag.
 13. The communication method of claim 12, further comprisingcommunicating with a combination tag by way of the third frequency andat least one of the first and second frequencies.